Brake Light Failures: MOT Implications

The MOT test is a crucial annual inspection designed to ensure your vehicle is safe and roadworthy. Among the many checks performed, the functionality of your brake lights is paramount. Failing to have properly working brake lights can have serious consequences, not only for your MOT certificate but also for your safety and the safety of others on the road. This article delves into what happens if your brake lights fail an MOT, the common reasons behind such failures, and what you can do to rectify the situation.

Understanding the MOT Brake Light Check

During an MOT test, a vehicle examiner will meticulously check the operation of all lights, including the brake lights. This involves ensuring that both the left and right brake lights illuminate when the brake pedal is depressed. They will also verify that the intensity and colour of the lights are correct, as per legal requirements. The absence of illumination, dim lights, or incorrect colours can all lead to an MOT failure. It's a simple check, but one that is often overlooked by drivers until it's too late.

Consequences of Brake Light Failure in an MOT

If your brake lights are found to be faulty during the MOT test, your vehicle will not pass. You will be issued with a refusal of an MOT certificate, along with a list of the defects found. While you can still drive your vehicle under certain circumstances if it has a valid MOT certificate, driving a vehicle with a dangerous defect, such as non-functioning brake lights, can lead to a penalty. You will need to have the necessary repairs carried out promptly and then present the vehicle for a partial re-test to demonstrate that the issue has been resolved. Failure to do so could result in fines and penalty points on your driving licence.

Common Causes for Brake Light Failure

Several factors can contribute to your brake lights failing to work. Understanding these common culprits can help you diagnose and potentially fix the problem before your MOT test:

• Bulb Failure: This is the most frequent reason. Brake light bulbs have a limited lifespan and can burn out over time. It's a simple and relatively inexpensive fix.
• Fuse Issues: The brake lights are connected to the vehicle's electrical system via a fuse. If this fuse blows, it will cut power to the brake lights. A blown fuse can be caused by a short circuit or simply by age.
• Wiring Problems: Damaged or corroded wiring can interrupt the electrical flow to the brake lights. This can happen due to wear and tear, or if the wiring has been exposed to moisture or physical damage.
• Faulty Brake Light Switch: Located near the brake pedal, this switch is responsible for activating the brake lights when the pedal is pressed. If the switch fails, the lights won't illuminate.
• Corroded Connections: The electrical connections to the bulbs or the switch can become corroded over time, leading to poor contact and intermittent or complete failure of the brake lights.
• Damaged Light Housing: While less common for functionality failure, a cracked or damaged light housing can allow moisture ingress, which can then lead to corrosion and electrical issues.

Diagnosing and Repairing Brake Light Issues

Before heading to your MOT test, it's wise to perform a basic check of your brake lights. Ask a friend or family member to stand behind your vehicle while you press the brake pedal. Visually confirm that both brake lights illuminate brightly and evenly. If they don't, you can start troubleshooting:

1. Check the Bulbs: The easiest step is to remove and inspect the brake light bulbs. Look for a broken filament or a blackened bulb. If you find one, replace it with a new one of the correct specification. Remember to check both brake lights.
2. Inspect the Fuse: Consult your vehicle's owner's manual to locate the fuse box and the specific fuse for the brake lights. Remove the fuse and check if the metal strip inside is broken. If it is, replace it with a new fuse of the same amperage.
3. Examine Wiring and Connections: If replacing bulbs and fuses doesn't solve the problem, you may have a wiring issue. This can be more challenging to diagnose. Look for any visible signs of damage, fraying, or corrosion in the wiring harness leading to the brake lights. Check the electrical connectors for any signs of corrosion or loose connections.
4. Test the Brake Light Switch: Testing the brake light switch usually requires a multimeter to check for continuity when the pedal is pressed. If you're not comfortable with electrical diagnostics, it's best to leave this to a qualified mechanic.

When to Seek Professional Help

While changing a bulb or a fuse is a straightforward DIY task, more complex electrical issues, such as wiring faults or a faulty brake light switch, often require the expertise of a qualified mechanic. They have the necessary tools and knowledge to accurately diagnose and repair these problems, ensuring your vehicle is safe and roadworthy.

Preventative Measures for Brake Light Functionality

To avoid an MOT failure due to faulty brake lights, consider these preventative measures:

• Regular Visual Checks: Make it a habit to check your brake lights regularly, perhaps once a month, or before any long journeys.
• Proactive Bulb Replacement: If your vehicle is older, consider replacing the brake light bulbs as a preventative measure, especially if they are the original ones.
• Keep Wiring Clean: Ensure that the areas around your light housings are kept clean and free from excessive dirt and debris, which can sometimes contribute to corrosion.
• Address Minor Issues Promptly: If you notice any intermittent flickering or dimming of your brake lights, get it checked out immediately rather than waiting for an MOT.

Table: Common MOT Failures Related to Lighting

While brake lights are a common failure point, other lighting issues can also cause an MOT failure. Here's a quick overview:

Frequently Asked Questions (FAQs)

Q1: Can I drive my car if my brake lights fail the MOT?
If your car fails the MOT due to brake lights, you can generally drive it to a pre-booked MOT test centre for a re-test, or to a place of repair. However, driving with a dangerous defect, such as non-functional brake lights, can lead to immediate penalties if stopped by the police, even if the MOT hasn't expired.

Q2: How much does it cost to fix brake lights for an MOT?
The cost can vary. Replacing a bulb is typically inexpensive, costing only a few pounds for the bulb itself, plus fitting time if done by a garage. Replacing a fuse is also very cheap. However, if the issue is with the wiring or the brake light switch, the cost will be higher, potentially ranging from £50 to £150 or more, depending on the complexity of the repair and labour rates.

Q3: Do I need to replace both brake light bulbs if one is out?
While you only need to replace the bulb that has failed, it's often good practice to replace both brake light bulbs at the same time. This is because the other bulb is of a similar age and may be close to failing itself. Replacing them in pairs ensures that they have a similar brightness and lifespan, and saves you the potential hassle of another failure soon after.

Q4: What if only one brake light is working?
If only one brake light is working, it will still result in an MOT failure. Both brake lights must be illuminated and functioning correctly when the brake pedal is pressed.

Q5: Can a faulty trailer connection affect my car's brake lights?
Yes, in some vehicles, the trailer light wiring can interfere with the car's own lighting system, potentially causing issues with the brake lights. If you tow a trailer, ensure the trailer's wiring is in good condition and correctly connected.

Conclusion

Ensuring your brake lights are in good working order is a straightforward but essential aspect of vehicle maintenance. A failure in this area during an MOT test is not only an inconvenience but also a safety hazard. By understanding the common causes of brake light failure and performing regular checks, you can significantly increase your chances of passing your MOT and, more importantly, ensure your vehicle is safe for you and everyone else on the road. Don't underestimate the importance of these vital signalling lights – keep them shining brightly!

If you want to read more articles similar to Brake Light Failures: MOT Implications, you can visit the MOT category.